1. Field of the Invention
The invention relates to an element for semiconductor package and more particularly, to a heat slug and a semiconductor package.
2. Description of the Related Art
Nowadays, since the speed of a chip is more and more fast, it has been an important topic in the art to efficiently dissipate heat from the semiconductor package when the chip is operated at a high rate. A simple method of dissipating heat from the chip is to configure a heat slug on the semiconductor package.
Referring to FIG. 1, it illustrates a conventional semiconductor package 90 provided with a heat slug. The semiconductor package 90 includes a substrate 91, a chip 92, a die adhesive 93, a plurality of bonding wires 94, a heat slug 95 and a sealant 96. The chip 92 is bonded to the substrate 91 through the die adhesive 93. The bonding wires 94 are used to electrically connect the chip 92 to the substrate 91. The heat slug 95 is disposed above the chip 92 and adhered to the substrate 91 through an adhesive 97. The semiconductor package 90 is encapsulated with the sealant 96. The heat slug 95 has a heat spreading member 951 and a supporting member 952. The heat spreading member 951 is exposed from the sealant 96 to facilitate heat dissipation. The supporting member 952 extends downward from the edge of the heat spreading member 951 and the tip of the supporting member 952 is substantially parallel to the substrate 91. The tip of the supporting member 952 is adapted to support the heat slug 95 on the substrate 91 and adhered to the substrate 91.
However, when the adhesive 97 is used to attach the heat slug 95 to the substrate 91, the adhesive 97 is not usually cured immediately. In the meantime, if the heat slug 95 is subjected to an external side force or a shock, for example, when the substrate 91 along with the heat slug 95 is placed in a curing oven to cure the adhesive 97, the tip of the supporting member 952 is likely to have an offset.
The Taiwan Patent No. 494556, entitled “SEMICONDUCTOR PACKAGE WITH HEAT SLUG” discloses a method for preventing the heat slug from offset. The semiconductor package includes a substrate, a semiconductor chip, a heat slug and a sealant. The substrate at least has a first embedded portion. The semiconductor chip is disposed on the substrate. The heat slug has an outer exposed portion and an inner connecting portion. The inner connecting portion extends from the edge of the outer exposed portion and at least has a second embedded portion to have the heat slug positioned in place on the substrate. The sealant encapsulates the semiconductor chip and the inner connecting portion and the outer exposed portion is exposed from the sealant. Although the second embedded portion can be embedded in the first embedded portion to have the heat slug positioned in place on the substrate, it is required to modify the substrate in order to form an indentation on the substrate as the first embedded portion. Besides, the first embedded portion will occupy the space for circuit wiring on the substrate. This will increase the complexity in designing and manufacturing the substrate when the area of the substrate and the pitch of the wiring become gradually small.
Accordingly, there exists a need to provide a heat slug to solve the above-mentioned problems.